JP-7139712-B2 - gravure or flexo ink

Inventors

• 成廣 治憲
• 小藤 通久

Assignees

• 東洋インキＳＣホールディングス株式会社
• 東洋インキＳＣホールディングス株式会社
• 東洋インキ株式会社
• 東洋インキ株式会社

Dates

Publication Date

20220921

Application Date

20180625

Priority Date

20180625

Claims (4)

1. A gravure or flexo ink containing a polyurethane resin (A) as a binder resin and an organic solvent, wherein the gravure or flexo ink satisfies the following requirements (1) to (4). (1) Polyurethane resin (A) contains a structural unit derived from polyester polyol consisting of a dibasic acid containing azelaic acid and a diol . (2) The polyurethane resin (A) contains 10% by mass or more of structural units derived from azelaic acid in the total mass . (3) The binder resin further contains at least one resin (B) selected from the group consisting of vinyl chloride copolymer resins, cellulose resins and rosin resins. (4) The binder resin is polyurethane resin (A) and resin (B), and the mass ratio (A):(B) of polyurethane resin (A) and resin (B) is 95:5 to 30:70. contains
2. 2. The gravure or flexo ink according to claim 1, wherein the polyurethane resin (A) further contains structural units derived from polyether polyol.
3. A printed matter comprising a base material 1 and a printed layer comprising the gravure or flexographic ink according to claim 1 or 2 .
4. A laminate having a substrate 2 on the printed layer of the printed matter according to claim 3 .

Description

The present invention relates to gravure or flexographic inks and their prints. More specifically, it relates to a gravure or flexo ink containing a polyurethane resin having a biomass component as a structural unit. In recent years, biomass-derived materials have been attracting attention as alternative materials against the depletion of petrochemical resources. Among them, sebacic acid and succinic acid, which are derived from biomass, are promising resin raw materials because polyester compounds thereof can be obtained. However, most conventional petroleum-derived polyester compounds are derived from adipic acid, which does not have a significant performance advantage over adipic acid-based polyester resins. becomes higher. Polyester compounds include, for example, polyester polyols, which are often used as raw materials for producing polyurethane resins. Polyurethane resins are useful as binder resins for gravure or flexographic printing inks, and have been favorably used because of their flexibility and good adhesion (Patent Documents 1 and 2). On the other hand, the gravure or flexographic inks are also required to be environmentally friendly by using biomass. Gravure or flexo ink is an industrially important printing technology because it has high productivity due to the characteristics of the printing method, high-speed printing and winding method, and can express high-definition patterns. Gravure or flexographic inks have relatively low ink viscosity, and because the printing machine is large, they are greatly affected by the temperature and humidity factors of the printing environment. In addition, there are cases where problems occur due to factors such as the temperature in which the printed matter and laminated laminate are placed. In particular, when the room temperature is low in the printing environment, problems such as plate fogging in gravure printing and plate entanglement in flexographic printing tend to occur. In addition, in a laminate laminate, since the polyurethane resin becomes hard at low temperatures, the laminate strength tends to decrease, and the amount of residual solvent in the printed matter tends to increase. Therefore, it is regarded as a problem in winter in Japan and in areas where the climate is low. JP 2016-150941 AJP 2018-44047 AJP 2018-62642 A Embodiments of the present invention will be described in detail below, but the description of the constituent elements described below is an example (representative example) of embodiments of the present invention, and the present invention does not exceed the gist thereof. Content is not limited. The gravure or flexo ink of the present invention will be described. Gravure or flexographic ink may be simply abbreviated as "ink" below, but is synonymous with gravure or flexographic ink. Further, the printing layer made of gravure or flexo ink is sometimes referred to as "printing layer", "ink layer" or "ink film", but is synonymous with the printing layer made of gravure or flexo ink. The present invention is a gravure or flexo ink containing a polyurethane resin (A) as a binder resin and an organic solvent, The total weight of the polyurethane (A) contains a structural unit derived from a polyester polyol composed of a dibasic acid containing azelaic acid and a diol, and the total weight of the polyurethane resin (A) contains 10% by weight of the structural unit derived from azelaic acid. gravure or flexographic ink containing the above. Azelaic acid is a dibasic acid obtained from fatty acids derived from vegetable and animal oils and has characteristic properties. Dibasic acids have an even and odd number of carbon atoms between carboxyl groups, which appears in the melting point and the like. For example, the melting point of azelaine, which has 7 carbon atoms between carboxyl groups, is 106° C., while the melting point of suberic acid, which has 6 carbon atoms between carboxyl groups, is 144° C., and zebacine, which has 8 carbon atoms between carboxyl groups. The melting point of the acid is 135°C. Therefore, a polyester polyol composed of azelaic acid and a diol is flexible and tough, and it is possible to obtain a polyurethane resin particularly excellent in low-temperature properties. Furthermore, when used in combination with a resin (B) described later, it exhibits better low-temperature properties as a gravure or flexographic ink. Such characteristics tend to be difficult to obtain when the azelaic acid-derived structure is not contained. <Binder resin> As used herein, the binder resin refers to a binder resin in gravure or flexo ink, and contains the following polyurethane resin (A). The binder resin is preferably contained in an amount of 2 to 15% by mass in the total mass of the ink, and the polyurethane resin is preferably contained in an amount of 40% by mass or more in the total mass of the binder resin. <Polyurethane resin (A)> The polyurethane resin (A) used in the present invention contains a structural uni